1. Field of the Invention
This invention relates to slide fasteners, and particularly to a stringer tape construction for a slide fastener.
2. Description of the Prior Art
A typical slide fastener includes a pair of stringers, each having a flexible tape with a row of coupling elements attached along one edge thereof, which are joined and separated by moving a slider along the pair of stringers.
Conventional slide fasteners include stringer tapes made of a textile fabric which provides a strong yet flexible mounting for the coupling elements. Other prior art fasteners, as exemplified by U.S. Pat. Nos. 3,885,275, 4,100,656 and 3,200,462, include non-fabric materials such as plastic films in their tapes, either alone or in conjunction with woven or knitted fabrics. One reason for using plastic films in fastener tapes is that they have a substantial cost advantage over conventional tape fabrics. However, known prior art non-fabric tapes have exhibited an unacceptable tendency to tear under load, either at the mounting points for the coupling elements or at the union between the tape and the article to which it is attached. A need exists for an improved non-fabric tape (that is, one which is neither woven nor knitted) that will better resist tearing failure, yet will provide adequate flexibility and a pleasing appearance in a low cost fastener.